By default, dictation isn't enabled after installing Mountain Lion on your Mac. If you want to use it, you're going to have to enable it.

The default shortcut to start dictation on your Mac is pressing the Function (Fn) key twice. The first time you try to start dictation, you'll be prompted to enable it.

As pointed out by a reader after this story was published, not all keyboards will have a Fn key. If that's the case with your keyboard, you can set the shortcut key in Dictation & Speech settings found in System Preferences.

Screenshot by Jason Cipriani/CNET

Click on OK.

Screenshot by Jason Cipriani/CNET

You're reminded one last time that anything you say while dictation is being used will be sent to Apple's servers. Click Enable Dictation to proceed.

Now that it's active, you can press the Fn key twice, in any text field, and begin speaking. Once you are done, you're required to either click Done on the dictation icon, or press the Fn key once. Otherwise, dictation will stay active listening for more input. You'll see three dots animate while your text is transcribed and then placed in the text field.

Keep in mind, Dictation will not place any punctuation (or correct your grammar) in the text it transcribes. If you want a comma, exclamation point, or period in your text, you have to speak it. For example, saying "This is me talking period" will be dictated as: